Gas analysis system

ABSTRACT

A gas analysis system includes a spectroscopy assembly coupled to a vehicle. The spectroscopy assembly includes a multiplexer configured to combine a plurality of light beams into a multiplexed light beam, wherein the multiplexer is configured to direct the multiplexed light beam toward a target surface. Additionally, the spectroscopy assembly includes a collection optic configured to receive a reflected multiplexed light beam from the target surface. Further, the spectroscopy assembly includes a controller configured to de-multiplex the multiplexed light beam into a plurality of reflected light beams and determine a spectral intensity of the plurality of reflected light beams.

TECHNICAL FIELD

The subject matter disclosed herein relates to gas analysis systems.Specifically, embodiments of the present disclosure relate to techniquesfor detecting a gas plume, characterizing the gas plume, and/ordetermining a flow rate of a gas generating the gas plume.

BACKGROUND

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the present disclosure,which are described below. This discussion is believed to be helpful inproviding the reader with background information to facilitate a betterunderstanding of the various aspects of the present disclosure.Accordingly, it should be understood that these statements are to beread in this light, and not as admissions of prior art.

Gas infrastructure (e.g., pipelines, well pads, etc.) incur wear overtime as a result of pressures at which gas is transported and stored,weather conditions, and/or other factors. Accurate gas detection isuseful to maintain efficient operation of the gas infrastructure.Moreover, providing additional characterization data (e.g., gas type,gas plume concentration, gas flow rate, etc.) may aid in determining acorrective action upon detection of a gas. However, the gasinfrastructure may span a wide area making it difficult to determine asource of gas and/or whether gas is present at a particular location.

BRIEF DESCRIPTION

In one embodiment, a gas analysis system includes a spectroscopyassembly coupled to a vehicle. The spectroscopy assembly includes amultiplexer configured to combine a plurality of light beams into amultiplexed light beam, wherein the multiplexer is configured to directthe multiplexed light beam toward a target surface. Additionally, thespectroscopy assembly includes a collection optic configured to receivea reflected multiplexed light beam from the target surface. Further, thespectroscopy assembly includes a controller configured to de-multiplexthe multiplexed light beam into a plurality of reflected light beams anddetermine a spectral intensity of the plurality of reflected lightbeams.

In another embodiment, a gas analysis system includes an unmanned aerialvehicle. Additionally, the gas analysis system includes a spectroscopyassembly coupled to the unmanned aerial vehicle. The spectroscopyassembly includes a multiplexer configured to combine a plurality oflight beams into a multiplexed light beam. Additionally, thespectroscopy assembly includes a scanning mirror configured to directthe multiplexed light beam toward a target surface. A collection opticconfigured to receive a reflected multiplexed light beam from the targetsurface. Further, a controller configured to de-multiplex the reflectedmultiplexed light beam into a plurality of reflected light beams. Thecontroller is configured to determine a spectral intensity of eachreflected light beam of the plurality of reflected light beams.

In a further embodiment, a method includes the step of combining aplurality of light beams into a single multiplexed light beam. Themethod also includes the steps of emitting the single multiplexed lightbeam toward a target surface and receiving a reflected multiplexed lightbeam from the target surface. Further, the method includes the step ofde-multiplexing the reflected multiplexed light beam into a plurality ofreflected light beams. Moreover, the method includes the step ofdetermining a spectral intensity of each reflected light beam of theplurality of reflected light beams.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is an elevation view of an embodiment of a gas analysis systemhaving a scanning platform, in accordance with an aspect of the presentdisclosure;

FIG. 2 is a block diagram of an embodiment of a spectroscopy assembly ofthe gas analysis system, in accordance with an aspect of the presentdisclosure;

FIG. 3 is a block diagram of an embodiment of the spectroscopy assemblyconfigured to multiplex light beam signals, in accordance with an aspectof the present disclosure;

FIG. 4 is a block diagram of an embodiment of a platform control system,in accordance with an aspect of the present disclosure;

FIG. 5 is a view of an embodiment of the gas analysis system emittingone or more light beams, in accordance with an aspect of the presentdisclosure;

FIG. 6 is a schematic of an embodiment of a collection optic of the gasanalysis system, in accordance with an aspect of the present disclosure;

FIG. 7 is an overhead view of an operational implementation of anunmanned vehicle having the gas analysis system, in accordance with anaspect of the present disclosure;

FIG. 8 is an overhead view of an embodiment of the unmanned vehicle gasanalysis system, in accordance with an aspect of the present disclosure;

FIG. 9 is an overhead view of an operational implementation of the gasanalysis system having a plurality of unmanned vehicles, in accordancewith an aspect of the present disclosure;

FIG. 10 is an overhead view of an operational implementation of the gasanalysis system configured to sweep the light beam along the flightpath, in accordance with an aspect of the present disclosure;

FIG. 11 is a perspective view of an operational implementation of theunmanned vehicle gas analysis system emitting one or more light beams ina multi-axis pattern, in accordance with an aspect of the presentdisclosure;

FIG. 12 is perspective view of an operational implementation of the gasanalysis system emitting one or more light beams to determineclassification data related to the gas plume, in accordance with anaspect of the present disclosure; and

FIG. 13 is a view of an operational implementation of a plurality ofunmanned vehicles analyzing the gas plume at various wind conditions, inaccordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

One or more specific embodiments will be described below. In an effortto provide a concise description of these embodiments, not all featuresof an actual implementation are described in the specification. Itshould be appreciated that in the development of any such actualimplementation, as in any engineering or design project, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one implementation toanother. Moreover, it should be appreciated that such a developmenteffort might be complex and time consuming, but would nevertheless be aroutine undertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

Typical gas analysis systems and methods may be configured to emit alight beam to detect a species of gas (e.g., tunable diode light beamabsorption spectroscopy, etc.). A gas analysis system may emit a lightbeam having a same wavelength of an absorption line of the species ofgas that the gas detection system is configured to detect. As usedherein, light beams refer to electromagnetic radiation that may includea wavelength between ten nanometers and one thousand meters.Accordingly, the light beams may include non-visible light (e.g.,ultraviolet light, infrared light, or microwaves) and/or visible light.Further, the light beams may include both organized beams of lightenergy that travel along a substantially linear path as well as diffusedlight energy that may include unorganized light energy that travelsalong a non-linear path. The gas analysis system may be configured toreceive the transmitted or reflected light beam to determine whether thespecies of gas is present. Traditional gas analysis systems may have lowsignal to noise ratios, which may lead to poor accuracy of gasdetection. As such, traditional gas analysis systems may requireincreased scan/detection times to increase accuracy of the gasdetection.

The systems and methods described herein relate to a gas analysis systemconfigured to emit one or more light beams toward a target surface,which may achieve a higher signal to noise ratio for detecting andcharacterizing gas and/or permit faster scan rates than traditionalsystems. Further, the gas analysis system may be configured to scan formultiple types of gases simultaneously, scan a larger target area,determine a shape of a gas plume (e.g., two-dimensional shape,three-dimensional shape or a volumetric classification), and/ordetermine gas concentration levels of the gas plume (e.g., a gasconcentration profile). Accordingly, the gas analysis system describedherein may provide for quicker and/or more accurate detection of gasplumes than traditional gas detection systems, as well as provideadditional information about the gas plume such as the shape andconcentration profile.

FIG. 1 is an elevation view of an embodiment of a gas analysis system10, in accordance with aspects of the present disclosure. In someembodiments, the gas analysis system 10 includes a scanning platformthat includes components configured to analyze a given area for a targetfluid. For example, the scanning platform may include an unmanned aerialvehicle 12, a manned aerial vehicle, an unmanned vehicle, a mannedvehicle, an automobile, a stationary structure with movable actuators,and/or any other suitable structure or device that includes a motionsystem capable of directing emitters over the given area. While thepresent discussion focuses on the scanning platform including theunmanned aerial vehicle 12, it should be recognized that the scanningplatform may include any suitable device. Therefore, the scanningplatform is configured to direct and/or carry a spectroscopy assembly 22for detecting and analyzing the target fluid (e.g., a gas).

In some embodiments, the scanning platform may include a main controller13 configured to control movement of scanning platform via instructionsoutput to a motion system 23 (e.g., a motor, an engine, an actuator, atleast one propeller, a steering system, a braking system, landing gear,gimbal motion stabilizer, or other suitable systems) of the scanningplatform. Furthermore, the main controller 13 is communicatively coupledto one or more subsystems 25 that may be utilized to provide feedbackindicative of the target fluid, a position of the scanning platform,conditions of an environment 15 surrounding the area being analyzed,and/or other parameters. The subsystems 25 may also include sub controlsystems, such as the motion system 23. While the subsystems 25 areincluded within the main controller 13 in FIG. 1, it should berecognized that the subsystems 25 may be separate control systems thatare communicatively coupled to the controller 13 wirelessly or via awired connection. In some embodiments, the gas analysis system 10includes an unmanned vehicle (e.g., the unmanned aerial vehicle 12 or aninspection drone) as the scanning platform. The unmanned aerial vehicle12 may be configured to move along a travel path 14 (e.g., a flightpath) within an environment 15 in which gas may be detected based atleast in part on instructions output from the main controller 13. Theflight path 14 may direct the unmanned aerial vehicle 12 to travel alonga pipeline, a well pad 16, and/or another component that may transportor store a gas. The unmanned aerial vehicle 12 may be configured todetect a location 18 of the well pad 16 that may supply gas into theenvironment 15.

As shown in the illustrated embodiment of FIG. 1, the unmanned aerialvehicle 12 may be directed over a gas plume 20 that forms around thelocation 18 of the well pad 16. In some embodiments, the gas analysissystem 10 includes the spectroscopy assembly 22 coupled to the unmannedaerial vehicle 12 so that the spectroscopy assembly 22 may obtain dataas the vehicle travels along the flight path 14. Components of thespectroscopy assembly 22 are coupled to a spectroscopy assembly housing24, and the spectroscopy assembly housing 24 may be coupled or mountedto the unmanned aerial vehicle 12. In the present embodiment, thespectroscopy assembly housing 24 is coupled to a bottom portion 26 ofthe unmanned vehicle 12. In other embodiments, the spectroscopy assemblyhousing 24 may be coupled to any suitable portion of the unmannedvehicle 12. In another embodiment, the spectroscopy assembly housing 24may be coupled to the gimbal motion stabilizer 27 mounted to theunmanned vehicle 12. The spectroscopy assembly 22 may be configured toemit one or more light beams 28 toward respective target surfaces 30 todetect gas. In the depicted example the respective target surfaces 30are located on a ground surface 32 below the gas plume 20. As theunmanned vehicle 12 travels along the flight path 14, the one or morelight beams 28 reflect off the target surfaces 30 back toward thespectroscopy assembly 22. The spectroscopy assembly 22 may then detectthe gas plume 20 based on a spectral intensity of the reflection of thelight beams 28 that pass through the gas plume 20. As used herein, thespectral intensity refers to a radiant intensity per unit of frequencyor wavelength.

In some embodiments, the spectroscopy assembly 22 may be configured todetermine whether a specific type of gas is present in the gas plume 20,such as based on the absorption or transmission of the one or more lightbeams 28 through the gas plume. For example, the spectroscopy assembly22 may be configured to emit a light beam 28 having a wavelength that isspecific to an absorption of the specific type of gas. Different typesof gases may have different absorption frequencies. As such, the lightbeam 28 having a specific wavelength and passing through the specifictype of gas may be reflected from the target surface 30 with a reducedspectral intensity that may be detected by the spectroscopy assembly 22.In some cases, the wavelength of the light beam 28 may not be absorbedby other types of gas, such that the spectroscopy assembly 22 may detectthe specific type of gas as a result of receiving reflected light thatincludes a spectral intensity that is below a threshold level.

In some embodiments, the spectroscopy assembly 22 is configured to tunethe light beam 28 over a range of wavelengths. The range of wavelengthsmay be centered around an absorption line of a specific type of gas. Theabsorption line may include at least one absorption frequency of thespecific type of gas. The range of wavelengths may include thewavelength corresponding to the absorption line, wavelengths above theabsorption line, and wavelengths below the absorption line. Tuning thelight beam to include the range of wavelengths may provide verificationdata to the spectroscopy assembly. For example, a first light beam maybe emitted at a first wavelength corresponding to a wavelength of theabsorption line and a second light beam may be emitted at a secondwavelength corresponding to a wavelength above the absorption line. Adrop in spectral intensity of the first light beam, but not the secondlight beam may provide verification data indicating that the light beampassed through the specific type of gas. However, a drop in the spectralintensity of both the first light beam and the second light beam mayprovide verification data indicating that another substance or object(e.g., another type of gas, ground surface, etc.) may be absorbing thefirst and second light beams.

Additionally or alternatively, the spectroscopy assembly 22 isconfigured to determine a shape 158 of the gas plume 20. Further, insome embodiments, the spectroscopy assembly 22 is configured todetermine a concentration of gas within a portion or throughout the gasplume 20 (e.g., determine a concentration profile of the gas plume 20).Further still the spectroscopy assembly 22 may be configured todetermine a flow rate of gas from the location 18 into the environment15.

FIG. 2 is a block diagram of an embodiment of the spectroscopy assembly22 of the gas analysis system 10. In some embodiments, the spectroscopyassembly 22 includes a controller 34 comprising an application specificintegrated circuit (ASIC) or a processor 36 and a memory device 38. Thememory device 38 may be configured to store instructions executable bythe processor 36 to perform the methods and to control actions describedherein. For example, the processor 36 may execute instructions stored onthe memory device 38 to control a signal generator 42 based on inputsindicating that the unmanned vehicle 12 is disposed proximate a targetlocation within the environment 15. The memory device 38 may also beconfigured to store data received during analysis of the targetlocation.

As shown in the illustrated embodiment of FIG. 2, the controller 34 mayinclude communications circuitry 40, such as antennas, radio transceivercircuits, signal processing hardware and/or software (e.g., hardware orsoftware filters, A/D converters, multiplexers, amplifiers), or acombination thereof. The communications circuitry 40 may be configuredto communicate over wired (e.g., serial ports: UART, RS-232, RS-485, CANbus, SPI, I2C, Ethernet, USB, etc.) or wireless communication paths(e.g., IR wireless communication, satellite communication, broadcastradio, microwave radio, Bluetooth, Zigbee, Wifi, UHF, NFC, etc.). Suchcommunication may also include intermediate communication devices, suchas radio towers, cellular towers, etc. In some embodiments, thecontroller 34 of the spectroscopy assembly 22 may be configured tocommunicate with the main controller 13 (shown in FIG. 4) of theunmanned vehicle 12 via the communications circuitry 40. For example,the controller 34 may output a data signal indicative of the data (e.g.,a change in spectral intensity of each of a plurality of light beams 28)received during inspection of the target location to the main controller13 over a wireless network via the communications circuitry 40. In someembodiments, the main controller 13 may utilize the signal to adjust theflight path 14 and/or perform another suitable action.

As set forth above, the spectroscopy assembly 22 may be configured todetermine a specific type of gas or gases that are present in the gasplume 20. Thus, the spectroscopy assembly 22 may be configured to causelight sources to emit one or more light beams 28 having respectivewavelengths that are specific to the absorption frequencies for one ormore target gases. The spectroscopy assembly 22 may include a signalgenerator 42 configured to generate a light beam signal 44 having thewavelength that is specific to the absorption frequency of a target gas.In some embodiments, the signal generator 42 may be configured togenerate a plurality of light beam signals 44. The signal generator 42may generate each light beam signal 44 of the plurality of light beamsignals 44 to have a respective wavelength corresponding to anabsorption frequency of a target gas based on instructions received fromthe controller 34. As such, each light beam signal 44 of the pluralityof light beam signals 44 may have a different wavelength. The signalgenerator 42 may output the plurality of light beam signals 44 to aplurality of light beam emitters 46 that generate the plurality of lightbeams 28. In some embodiments, the signal generator 42 may be configuredoutput each light beam signal 44 of the plurality of light beam signals44 to a respective light beam emitter 46 of the plurality of light beamemitters 46.

The plurality of light beam emitters 46 may be configured to emit eachrespective light beam 28 of the plurality of light beams 28 toward arespective target surface 30 (or to a common target surface 30). In someembodiments, each light beam emitter 46 of the spectroscopy assembly 22may include at least one light beam diode (e.g., a light emitting diode)configured to generate the light beam in response to the light beamsignal 44. Each light beam emitter 46 may also include a focusing lensconfigured to focus the light beam 28 generated by the light beam diode.In some embodiments, the focusing lens is oriented such that the lightbeam 28 is directed through the focusing lens toward a respective targetsurface 30. Each light beam 28 of the plurality of light beams 28 mayreflect off of the respective target surface 30 in a direction toward acollection optic 48 of the spectroscopy assembly 22. The collectionoptic 48 may receive reflected light beams 50 reflected from therespective target surfaces 30. Specifically, the reflected light beams50 may pass through the collection optic 48, which may focus thereflected light beams 50 onto at least one detector 52 (e.g., photodetector) of the spectroscopy assembly 22.

In some embodiments, the at least one detector 52 is configured todetect the reflected light beam 50. In some embodiments, a singledetector 52 is configured to detect a plurality of reflectedwavelengths. In other embodiments, the spectroscopy assembly 22 includesa plurality of detectors 52, where each detector 52 is configured todetect a respective emitted wavelength. For instance, the spectroscopyassembly 22 may include a detector 52 corresponding to each emittedwavelength. The at least one detector 52 may output a reflected lightbeam signal 54 based at least in part on the reflected light beam 50detected by the at least one detector 52. The reflected light beamsignal 54 may be based at least in part on a spectral intensity,wavelength, frequency, directionality, another suitable parameter, orany combination thereof of the reflected light beam 50 detected by thedetector 52. In some embodiments, the spectroscopy assembly 22 includesa signal conditioner 56 configured to receive the reflected light beamsignal 54 which may be an analog signal. The signal conditioner 56 maybe configured to process or condition (e.g., pre-amplify, filter, etc.)the reflected light beam signal 54 and convert the reflected light beamsignal 44 into a digital reflected light beam signal 55. In someembodiments, the signal conditioner 56 may consolidate multiplereflected light beam signals 54 into a single digital reflected lightbeam signal 55 that is received by the controller 34. In otherembodiments, the signal conditioner 56 may send individual digitalreflected light beam signals 55 to the controller 34 that correspond toeach of the reflected light beam signals 54. The signal conditioner 56may send a plurality of digital reflected light beam signals 55 to thecontroller 34 simultaneously or send the signals in series.

In some embodiments, the controller 34 is configured to receive thedigital reflected light beam signal 55. The controller 34 may beconfigured to analyze and post-process the digital reflected light beamsignal 55. In some embodiments, the controller 34 includes a digitallock-in amplifier configured to analyze the digital reflected light beamsignal 55. In some embodiments, the controller 34 may include an analogmixer or demodulator to analyze the digital reflected light beam signal55. Additionally or alternatively, the controller 34 may include asignal processor 58 (e.g., a digital signal processing unit) configuredto post-process the digital reflected light beam signal 55. Thecontroller 34 may be configured to determine a change in spectralintensity of the light beam from emission at the light beam emitter todetection at the detector 52 based at least in part on the analysis andpost-processing of the digital reflected light beam signal 54. A changein spectral intensity of the light beam may indicate that the light beampassed through a gas plume 20 of a type of gas configured to be detectedby the light beam. Thus, the spectroscopy assembly 22 may be configuredto detect gas based at least in part on a change in spectral intensityof the respective light beams 28.

In some embodiments, the spectroscopy assembly 22 may be configured todetect multiple types of gases. For example, the controller 34 may beconfigured to determine that a first type of gas present in the gasplume 20 based at least in part on the change of in spectral intensityof a first light beam 100 having a first wavelength relevant to themeasurement of the first type of gas. For example, the first light beam100 may have a wavelength corresponding to an absorption frequency ofthe first target gas. Further, the controller 34 may be able todetermine a second target gas that is present in the gas plume 20 basedat least in part on the change in spectral intensity of a second lightbeam 104 having a different wavelength relevant to the measurement ofthe second type of gas. The second light beam 104 may have a wavelengthcorresponding to an absorption frequency of the second target gas. Thefirst light beam 100 may be emitted from a first light beam emitter 46and the second light beam 104 may be emitted from a second light beamemitter 46 in order to facilitate emission of the different wavelengths.However, in some embodiments, a single light beam emitter may beconfigured to output a plurality of light beams 28 (e.g., the first andsecond light beams 100, 104) at different wavelengths.

In some embodiments, the spectroscopy assembly 22 may be configured todetect multiple target gases using a single light beam emitter that isconfigured to output a tunable light beam. For example, the spectroscopyassembly 22 may include a tunable diode light beam absorptionspectroscopy (“TDLAS”) sensor. The spectroscopy assembly 22 may includea tunable diode that tunes the tunable light beam to a plurality oftarget wavelengths based at least in part on instructions from thecontroller 34. The spectroscopy assembly 22 may adjust the temperatureof the tunable diode to cause the tunable diode to emit the tunablelight beam having the plurality of target wavelengths. However, anysuitable adjustment technique may be used to adjust the tunable diode.The detector 52 may be configured to receive the reflected tunable lightbeam and separate or otherwise distinguish the individual beams of thetunable light beam. As such, the spectroscopy assembly 22 may beconfigured to determine changes in spectral intensity of the tunablelight beam for each wavelength of the plurality of target wavelengths. Achange in spectral intensity of the tunable light beam at a wavelengthof the plurality of target wavelengths may indicate that the tunablelight beam passed through a gas plume 20 of a target gas associated withthe wavelength. The spectroscopy assembly 22 may determine changes inspectral intensity at multiple wavelengths to detect multiple targetgases using the single light beam emitter that outputs the tunable lightbeam.

FIG. 3 is a block diagram of an embodiment of the spectroscopy assembly22 of FIG. 2 configured to multiplex the light beam signals 44. As setforth above, the spectroscopy assembly 22 includes the controller 34configured to instruct the signal generator 42 to output the pluralityof light beam signals 44. In the illustrated embodiment, thespectroscopy assembly 22 includes a multiplexer 60 (e.g., an opticalfiber multiplexer) that receives the plurality of light beam signals 44output from the emitters 46. The multiplexer 60 may be configured tocombine the plurality of light beams 28 into a single light beam signal(e.g., multiplexed light beam signal 188) and output the multiplexedlight beam signal 188. In some embodiments, the multiplexer 60 includesa light beam collimator 62 that may receive the multiplexed light beamsignal 188 and output a multiplexed light beam 190. The light beamcollimator 62 may be configured to collimate the multiplexed light beamsignal 188 to generate the multiplexed light beam 190 by narrowing themultiplexed light beam signal 188 to align the multiplexed light beamsignal 188 in a specific direction or to cause a spatial cross sectionof the multiplexed light beam signal 188 to become smaller. The lightbeam collimator 62 may then direct the multiplexed light beam 190 towardthe target surface 30.

As shown in the illustrated embodiment of FIG. 3, the light beamcollimator 62 is configured to direct the multiplexed light beam 190toward a scanning micro-mirror 64. The multiplexed light beam 190 mayreflect off of the scanning micro-mirror 64 toward the target surface30. The scanning micro-mirror 64 may be configured to rotate withrespect to a light beam sensor housing 65. Thus, the scanning-micromirror 64 may be configured to direct the multiplexed light beam 190toward the target surface 30. In some embodiments, the scanningmicro-mirror 64 is configured to rotate to sweep (e.g., oscillate orotherwise move) the multiplexed light beam 190 along the ground surface32. Sweeping the light beam may increase a scanning range 66 of thespectroscopy assembly 22 as the unmanned vehicle 12 travels along theflight path 14. For example, the multiplexed light beam 190 may bedirected vertically downward toward the ground surface 32 as theunmanned vehicle 12 travels in an operating direction 67. Rotating thescanning micro-mirror 64 may direct the light beam between a left targetsurface 68 disposed on a left side of the scanning range 66 and a righttarget surface 70 disposed on a right side of the scanning range 66.Without rotating the scanning micro-mirror 64, the scanning range 66 ofthe spectroscopy assembly 22 may be reduced and include an area coveredby one of the target surfaces 68, 70. Rotating or otherwise moving thescanning micro-mirror 64 may increase the scanning range 66 and enablethe multiplexed light beam 190 to cover a larger surface area as theunmanned vehicle 12 is directed along the flight path 14. In someembodiments, the scanning micro-mirror 64 may include multiple degreesof movement (e.g., rotation about multiple axes) to enable the scanningmicro-mirror 64 to direct the multiplexed light beam 190 toward thetarget surface 30.

The multiplexed light beam 190 may be configured to reflect off of thetarget surface 30 in a direction toward the collection optic 48. Thereflected multiplexed light beam 192 may pass through the collectionoptic 48, and the collection optic 48 may focus the reflectedmultiplexed light beam 192 onto the at least one detector 52 of thespectroscopy assembly 22. The at least one detector 52 is configured todetect the reflected multiplexed light beam 192, and output a reflectedmultiplexed light beam signal 193 based at least in part on thereflected multiplexed light beam 192 detected by the at least onedetector 52. The spectroscopy assembly 22 may include a signalconditioner 56 configured to receive the reflected multiplexed lightbeam signal 193, which may be an analog signal. The signal conditioner56 is configured to process or condition (e.g., pre-amplify, filter,etc.) the reflected multiplexed light beam signal 193 and convert thereflected multiplexed light beam signal 193 into a digital reflectedmultiplexed light beam signal 189.

In some embodiments, the controller 34 is configured to receive thedigital reflected multiplexed light beam signal 189 to analyze andpost-process the digital reflected multiplexed light beam signal 189. Insome embodiments, the controller 34 or the signal conditioner 56includes a demultiplexer 76 configured to demultiplex the digitalreflected multiplexed light beam signal 189 into a plurality of digitalreflected light beam signals 54. As used herein, demultiplex may includeseparating a single signal (e.g., the digital reflected multiplexedlight beam signal 189) into multiple separate signals. Accordingly, thedemultiplexer 76 essentially reverses the process of the multiplexer 60.The controller 34 may be configured to determine a change in spectralintensity of each respective light beam of the plurality of digitalreflected light beam signals 54. A change in spectral intensity of arespective light beam may indicate that the respective light beam passedthrough the gas plume 20 having a target gas configured to be detectedby a corresponding light beam of the multiplexed light beam 190. Thus,the spectroscopy assembly 22 may be configured to detect gas based atleast in part on a change in spectral intensity of a respective lightbeam of the multiplexed light beam 190. Moreover, the spectroscopyassembly 22 may be configured to detect multiple target gases based atleast in part on a change in spectral intensity of respective lightbeams 28 of the multiplexed light beam 190.

FIG. 4 is a block diagram of an embodiment of a platform control system78 that may be included in the unmanned vehicle 12 or in anothersuitable scanning platform 12. The platform control system 78 (e.g.,unmanned aerial vehicle control system) may include a main controller13. The main controller 13 may be configured to control the unmannedvehicle 12 to execute the flight path 14. Specifically, the maincontroller 13 may be configured to output a motion control signal 81 tothe motion system 23. As set forth above, the motion system 23 mayinclude at least one propeller, at least one motor, an engine, anactuator, a steering system, a braking system, landing gear, or othersuitable systems. The motion control signal 81 may include instructionsto the motion system 23 that move the unmanned vehicle along the flightpath 14. For example, the main controller 13 may be configured to outputthe motion control signal 81 to the motion system 23, where the motioncontrol signal includes instructions to drive a propeller of theunmanned vehicle 12, such that the unmanned vehicle 12 travels along theflight path 14. The main controller 13 may be configured to controlvehicle systems to maintain a desired height and/or speed of theunmanned vehicle 12. For example, the main controller 13 may beconfigured to instruct the unmanned vehicle 12 to lower its height andposition the unmanned vehicle 12 closer to the target surface 32 upondetecting a target gas. In some embodiments, the main controller 13 isconfigured to cause the unmanned vehicle 12 to move with respect to aroll axis, a yaw axis, and/or a pitch axis to aim the plurality of lightbeams 28 emitted from the spectroscopy assembly 22 toward respectivetarget surfaces 30. The platform control system 78 may include anorientation sensor 82 configured to detect an orientation (e.g., degreesof rotation about the roll axis, the yaw axis, and/or the pitch axis) ofthe unmanned vehicle 12 with respect to the ground surface 32 and thedirection of travel 67 of the unmanned vehicle 12. The orientationsensor 82 may output the orientation of the unmanned vehicle 12 to themain controller 13.

In some embodiments, the platform control system 78 includes a globalpositioning sensor 84 configured to detect a current location of theunmanned vehicle 12 along the flight path 14 and/or with respect to theground surface 32. The main controller 13 may be configured to controlthe systems of the unmanned vehicle 12 based at least in part on apredetermined flight path 14 for the unmanned vehicle 12 and the currentlocation of the unmanned vehicle 12. Moreover, the main controller 13may tag data received from the spectroscopy assembly 22, a thermalimager 86, a video imager 88 (e.g., RGB video imager), or a light anddetection ranging (“LIDAR”) sensor 90 with the current location of theunmanned vehicle 12 and save geotagged data (e.g., the received datawith the respective current location) on a vehicle memory device 38. Themain controller 13 may be configured to output the geotagged data to anetwork, the controller 34, and/or another computing device.

In some embodiments, the LIDAR sensor 90 is configured to detect atopology, terrain, type, or other characteristic of the target surface30 and/or the ground surface 32. For example, the LIDAR sensor 90 maydetect that the ground surface 32 includes sand, grass, soil, rocks,gravel, or any combination thereof. The LIDAR sensor 90 may beconfigured to output data related to the target surface 30 and/or theground surface 32 to the main controller 13. In some embodiments, themain controller 13 may determine a reflectivity of the target surface30, and thus, adjust analysis parameters based on the determinedreflectivity of the target surface 30. Further, the main controller 13may be configured to adjust the flight path 14 based at least in part onthe topology of the target surface 30.

In some embodiments, the main controller 13 is also configured toreceive inputs from a user interface 92. The inputs from the userinterface 92 may include instructions related to the flight path 14and/or deviations from a previous flight path 14, which may be at leastpart of the motion control signal 81 to the motion system 23. Moreover,the main controller 13 may receive inputs related to target gases thatmay be detected within the environment 15. Accordingly, the maincontroller 13 may instruct the spectroscopy assembly 22 to output lightbeams at a specific wavelength corresponding to the target gases basedon the inputs received from the user interface 92. In some embodiments,the controller 34 of the spectroscopy assembly 22 is configured toreceive inputs directly from the user interface 92. In otherembodiments, the main controller 13 is configured to output instructionsto the spectroscopy assembly 22 and/or one or more other of thesubsystems 25 based at least in part on inputs received from the userinterface 92.

In some embodiments, the platform control system 78 includes the thermalimager 86 configured to capture a one or more thermal images of an areaproximate the unmanned vehicle 12, such as the target surface 30. Thethermal imager 86 may continuously capture thermal images as theunmanned vehicle 12 travels along the flight path 14. In otherembodiments, the thermal imager 86 is configured to capture thermalimages at a preset interval (e.g., every second, every 10 seconds, every30 seconds, or every minute). Additionally or alternatively, the thermalimager 86 is configured to capture thermal images of specified objects,surfaces, and/or locations within the environment 15. For example, thethermal imager 86 may capture the one or more thermal images of thelocation 18 at which gas enters the environment 15. The thermal imager86 is configured to output the thermal images to the main controller 13,which may determine that the gas plume 20 is present and/or analyze thegas plume 20 based on an analysis of the thermal images. For instance,the main controller 13 may determine a general shape and size of the gasplume 20, a temperature of the gas plume 20, a concentrationdistribution of the gas plume 20, or other characteristics of the gasplume 20 based on the thermal images received from the thermal imager86.

In some embodiments, the platform control system 78 includes a red,green, blue (“RBG”) video imager. The RGB video imager 88 may beconfigured to capture visual video images of the target surfacesproximate the gas plume 20. The RGB video imager 88 may output thevisual video images to the main controller 13, and the main controller13 may save the visual video images on the vehicle memory device 38. Insome embodiments, the main controller 13 may analyze the visual videoimages to determine a condition of the location 18 where gas enters theenvironment 15. In other embodiments, the main controller 13 isconfigured to output the visual video images to the user interface 92such that the user may analyze the visual video images and determine acondition of the location where gas enters the environment 15.

Moreover, the platform control system 78 may include the spectroscopyassembly 22. As set forth above, the spectroscopy assembly 22 may beconfigured to detect gas and/or a type of gas based at least in part ona change in spectral intensity of the light beam 28 emitted from theemitter 46 and reflected back to the detector 52 of the spectroscopyassembly 22. The controller 34 of the spectroscopy assembly 22 may becommunicatively coupled to the main controller 13, and thus, thecontroller 34 may send feedback indicative of a detection of gas or atype of gas to the main controller 13. However, in other embodiments,the spectroscopy assembly 22 may be integrated into the platform controlsystem 78 such that the spectroscopy assembly 22 does not include adedicated or separate controller (e.g., the controller 34) and the maincontroller 13 functions as the controller for the spectroscopy assembly22. For example, the signal generator 42 of the spectroscopy assembly 22may generate each light beam signal 44 of the plurality of light beamsignals 44 to have a specific wavelength based on instructions receivedfrom the main controller 13. Additionally, the main controller 13 may beconfigured to determine the type of gas present in the gas plume 20based at least in part on the change in spectral intensity of a lightbeam 28 of the plurality of light beams 28. In some embodiments, themain controller 13 is also configured to analyze the gas plume 20 (e.g.,determine the shape 158 or a concentration of the gas plume 20) based atleast in part on changes in spectral intensity of the plurality of lightbeams 28.

In some embodiments, the platform control system 78 includes asupplemental sensor 94 (e.g., a flow sensor, an accelerometer, apiezoelectric sensor, or another suitable sensor) configured to detect awind condition at a location of the unmanned vehicle 12. Thesupplemental sensor 94 may output a wind condition signal, indicatingthe wind condition, to the main controller 13. In some embodiments, theunmanned vehicle 12 may be above the gas plume 20 with respect to theground surface 32, such that the wind condition may be different at thelocation of the unmanned vehicle 12 than the location of the gas plume20. For example, the wind condition at the unmanned vehicle 12 mayinclude wind blowing in a first direction at fifteen miles per hour(“mph”), and the wind condition at the gas plume 20 may include windblowing in a second direction at twelve mph. Thus, in response todetecting the gas plume 20, the platform control system 78 may lower theheight of the unmanned vehicle 12 toward the gas plume 20 to obtain amore accurate wind condition from the supplemental sensor 94. In otherembodiments, the main controller 13 may be configured to receive thewind condition over a network (e.g., the Internet) and/or from anotherdevice external to the main controller 13 and the unmanned vehicle 12.

In some embodiments, the unmanned vehicle 12 includes a velocity sensor96 configured to detect a velocity of the unmanned vehicle 12. Thevelocity sensor 96 may output a velocity signal indicative of thedetected velocity to the main controller 13. The main controller 13 maybe configured to determine an actual wind condition based at least inpart on the wind condition signal from the supplemental sensor 94 andthe velocity signal from the velocity signal 96.

In some embodiments, the main controller 13 may be configured todetermine a gas flow rate from the location 18 directing gas into theenvironment 15 to form the gas plume 20 based at least in part on theactual wind condition, the shape 158 of the gas plume 20, and theconcentration of the gas plume 20. For example, the main controller 13may determine a gas flow rate based on a change in volume of the gasplume 13 in response to a signal indicative of the shape 158 of the gasplume 20 increasing in size (e.g., volume of the gas plume 20increasing), a signal indicative of the gas concentration of the gasplume 20 remaining substantially constant, and a signal indicative of noactual wind condition (e.g., no wind is currently blowing).

FIG. 5 is a perspective view of an embodiment of the gas analysis system10 having the unmanned aerial vehicle (e.g., unmanned vehicle 12)emitting the plurality of light beams 28. The unmanned vehicle 12 maytravel along the flight path 14 at a height 98 from the ground surface32 based at least in part on the flight path 14. In some embodiments,the height 98 is between one foot and one hundred feet, between fivefeet and fifty feet, or between 3 feet and 15 feet above the groundsurface 32. The height of the unmanned vehicle 12 may change as theunamend vehicle 12 moves along the flight path 14. In some embodiments,the height of the unmanned vehicle 12 may change along the flight path14 based on the topology of the inspection area (e.g., the targetsurface 30) at specific points along the flight path 14. For example, ina wooded area with tall trees, the flight path 14 may cause the unmannedvehicle 12 to increase the height 98 such that the unmanned vehicle 12maintains a minimum distance above the trees (e.g., the path of theunmanned vehicle 12 is unobstructed by the trees). In some embodiments,the flight path 14 may cause the height 98 of the unmanned vehicle 12 tomove up and down based on the topology of the inspection area along theflight path 14 to maintain a constant height of the unmanned vehicle 12with respect to the ground surface 32. Additionally or alternatively,the flight path 14 is based at least in part on the wind condition orother parameter affecting flight of the unmanned vehicle 12 or the scan.For example, a wind speed at fifty feet above the ground surface 32 maybe thirty mph, and a wind speed twenty feet above the ground surface 32may be ten mph. The main controller 13 may adjust the flight path 14 tolower the unmanned vehicle 12 to twenty feet above the ground to fly theunmanned vehicle 12 with a lower wind speed.

The unmanned vehicle 12 may include a plurality of light beam emitters46 configured to emit each light beam 28 of a plurality of light beams28 toward a respective target surface 30. As shown in the illustratedembodiment of FIG. 5, the plurality of light beam emitters 46 emits afirst light beam 100 toward a first target surface 102, a second lightbeam 104 toward a second target surface 106, and a third light beam 108toward a third target surface 110. Each light beam 100, 104, 108 of theplurality of light beams 28 may be emitted at a different angle withrespect to the unmanned vehicle 12 (and/or the ground surface 32), suchthat each light beam 100, 104, 108 of the plurality of light beams 28includes an angular offset from each other. For example, the first lightbeam 100 may be offset from the second light beam 104 by a first angle112, the first light beam 100 may be offset from the third light beam108 by a second angle 114, and the second light beam 104 and the thirdlight beam 108 may be offset by a third angle 116.

In some embodiments, the first light beam 100 may be emitted directlydownward (e.g., along a z-axis 166) by the plurality of light beamemitters 46 from the unmanned vehicle 12. As the first light beam 100 isemitted directly downward, a first height 120 from the spectroscopyassembly 22 to the first target surface 102 may be the height 98 of theunmanned vehicle 12 from the ground surface 32. For example, for anunmanned vehicle 12 flying at a height of ten feet, the first height 120may be ten feet. As a non-limiting example, the first angle 112 (e.g.,angle between the first light beam 100 and the second light beam 104)may be two degrees. Thus, a first distance 122 between the first targetsurface 102 and the second target surface 106 may be approximately(e.g., within 10% of, within 5% of, or within 1% of) four inches.Lowering the height of the unmanned vehicle 12 may increase a resolutionof the scan, but decrease the scanning range 66. The resolutionincreases as the plurality of target surfaces 102, 106, 110 move closertogether (e.g., decrease the first distance 122), but scanning range 66also decreases as the target surfaces 102, 106, 110 move closertogether. Thus, the unmanned vehicle 12 may control the scanning range66 and the resolution of the scan based at least in part on the height98 of the unmanned vehicle 12.

In some embodiments, the first angle 112 and then second angle 114 maybe substantially equal. For example, the first angle 112 may be twodegrees and the second angle 114 may be two degrees. However, in otherembodiments, the first angle 112 and the second angle 114 may havedifferent values. For example, the first angle 112 may be five degreesand the second angle 114 may be forty-five degrees. Additionally oralternatively, the spectroscopy assembly 22 is configured to change thefirst angle 112 and/or the second angle 114, via the scanningmicro-mirror 64 and/or additional mirrors that may be included in thespectroscopy assembly 22. For example, the first angle 112 may befifteen degrees during a first portion of the flight path 14. During asecond portion of the flight path 14, the first angle 112 may beadjusted (e.g., via the scanning micro-mirror 64) to five degrees. Insome embodiments, the spectroscopy assembly 22 may be configured tochange the first angle 112 and/or the second angle 114 in response todetection of the gas plume 20. The spectroscopy assembly 22 may decreasethe first angle 112 and/or the second angle 114 to increase theresolution of the scan. However, to help detect a shape 158 of the gasplume 20, the spectroscopy assembly 22 may increase the first angle 112and/or the second angle 114 to increase the scanning range 66.

In some embodiments, the second light beam 104 and the third light beam108 may be offset from the first light beam 100, such that the firsttarget area 102, the second target area 106, and the third target area110 form a row 124 (e.g., a linear line) on the ground surface 32.Aligning the plurality of light beams 28 in the row 124 may increase thescanning range 66 and enhance an accuracy and efficiency of detection ofthe gas plume 20.

FIG. 6 is a side view of an embodiment of a collection optic 48 of thegas analysis system 10. The collection optic 48 may be configured toreceive each light beam 28 of the plurality of light beams 28 and directthe plurality of light beams 28 to a respective detector 52. As shown inthe illustrated embodiment of FIG. 6, the collection optic 48 isconfigured to direct the plurality of light beams 28 to a first detector126, a second detector 128, and/or a third detector 130. The collectionoptic 48 may be configured to direct a light beam 28 to one of thedetectors 126, 128, 130 based at least in part on an angle of the lightbeam 28 with respect to the collection optic 48. The angle of the lightbeam 28 with respect to the collection optic 48 may correspond to anangle at which the angle was emitted from the emitter 46 of thespectroscopy assembly 22. In some embodiments, the collection optic 48includes a condenser lens 132. The condenser lens 132 may include glass,such that the condenser lens 132 is transparent over a large wavelengthrange. Alternatively, the condenser lens 132 may include a polymericmaterial and/or another suitable material.

In other embodiments, the collection optic 48 is a Fresnel lens. Fresnellenses may generally be thinner than other collection optics 48, andthus, may be lighter than other optics. In still further embodiments,the collection optic 48 may be a parabolic concentrator (e.g., a Winstoncone). Parabolic concentrators are generally well suited for gatheringbackscattered light beams 28 and redirecting the backscattered lightbeams 28 to the detector 52. The spectroscopy assembly 22 may include asingle collection optic 48 configured to receive the plurality of lightbeams 28 and direct the plurality of light beams 28 to the respectivedetector 52. In other embodiments, the spectroscopy assembly 22 mayinclude multiple collection optics 48 (e.g., two, three, four, five,six, seven, eight, nine, ten, or more than ten of the collection optics48). Further, in some embodiments, the spectroscopy assembly includesmultiple types of collection optics. Specifically, the spectroscopyassembly may include some combination of a condenser lens, a Fresnellens, and/or a parabolic concentrator.

FIG. 7 is a perspective view of an embodiment of the gas analysis system10 having an unmanned vehicle (e.g., inspection drone 12) following theflight path 14 along a pipeline 134 (e.g., a pipeline buried beneath theground surface 32) to detect the gas plume 20. In some embodiments, theflight path 14 may be configured to direct the unmanned vehicle 12 overthe pipeline 134 to inspect the pipeline 134 for the location 18 thatmay be the source of the gas plume 20. The flight path 14 may beconfigured to follow a length of the pipeline 134. While a portion ofthe pipeline 134 shown in FIG. 7 is substantially linear, it should benoted that other portions of the pipeline 134 may include bends, curves,elbows, angles, or other suitable features. In some embodiments, theunmanned vehicle 12 is configured to be positioned directly above thepipeline 134 as the inspections drone travels along the length of thepipeline 134, such that the first target surface 102 includes at least aportion of the pipeline 134. In some embodiments, the first targetsurface 102 may include at least a portion of a surface disposed abovethe pipeline 134 (e.g., a ground surface 32 above a buried portion ofpipeline 134).

In some embodiments, the emitters 46 are configured to emit theplurality of light beams 28 to detect the gas plume 20. As shown in theillustrated embodiment of FIG. 7, the emitters 46 are configured to emitthe first light beam 100, the second light beam 104, and the third lightbeam 108. The second light beam 104 and the third light beam 108 areoffset from the first light beam 100, such that the first target surface102, the second target surface 106, and the third target surface 110form the row 124 (e.g., a linear line) on the ground surface 32. As theunmanned vehicle 12 travels in a direction 138, the row 124 of targetsurfaces moves with respect to the unmanned vehicle 12. The first angle112 and the second angle may be configured to position the second targetsurface 106 and the third target surface 110 proximate the pipeline 134.Positioning the second and third target surfaces 106, 110 proximate thepipeline 134 may increase the resolution of the scan to detect small gasplumes 20 that may be disposed between the target surfaces. Moving thetarget surfaces closer together (e.g., reducing the first angle 112 andthe second angle 114) may increase the resolution and enable thespectroscopy assembly 22 to better detect the small gas plumes 20. Thespectroscopy assembly 22 may lower the height 98 of the unmanned vehicle12 to increase the resolution of the scan and/or utilize the scanningmicro-mirrors 64 to reduce the first and second angles 112, 114 andimprove the resolution of the scan.

FIG. 8 is a perspective view of an embodiment of the gas analysis system10 following the flight path 14 over a well pad 16 to detect a gas plume20 at the well pad 16. A width of the well pad 16 may be too large toadequately inspect the well pad 16 with a single pass of the unmannedvehicle 12. Thus, as shown in the present embodiment, the flight path 14may be configured to direct the unmanned vehicle 12 to traverse (e.g.,move back and forth) over a span of the well pad 16 in a serpentinemanner. However, the flight path 14 may be configured to follow anyroute suitable for directing the unmanned vehicle 12 to scan an entirearea of the well pad 16.

FIG. 9 is a perspective view of an embodiment of the gas analysis system10 having a plurality of scanning platforms 12 (e.g., inspection drones184) following respective flight paths 14 over a well pad 16 to detectthe gas plume 20. To facilitate inspection of the well pad 16, theplurality of unmanned vehicles 184 may be configured to scan the wellpad 16 and cover a larger area than a single unmanned vehicle. Theplurality of unmanned vehicles 184 may be configured to receiverespective flight paths 14 from the user interface 92. In someembodiments, a plurality of user interfaces 92 may be configured tooutput the respective flight paths 14 to each of the unmanned vehicles184. In another embodiment, each main controller 13 of the respectiveplurality of inspection vehicles is configured to follow a predeterminedflight path 14 stored on a respective vehicle memory.

In some embodiments, the plurality of unmanned vehicles 184 areconfigured to scan the area of the well pad 16, such that the pluralityof target surfaces corresponding to the respective unmanned vehicles 184are oriented in the row. Orienting the target surfaces in the row alongthe well pad 16 may increase accuracy of a scan during gusting winds194. For example, the plurality of unmanned vehicles 184 may include atleast a first unmanned vehicle 140 and a second unmanned vehicle 142.The location 18 of the source of the gas plume 20 in the well pad 16 maybe disposed along the flight path 14 of the first unmanned vehicle 140.The first and second unmanned vehicles 140, 142 may be moving in a firstdirection 144 along the well pad 16. The second unmanned vehicle 142 maybe disposed adjacent to the first unmanned vehicle 140 with respect to adirection 146. Moreover, the second unmanned vehicle 142 may be disposedbefore the first unmanned vehicle 140 with respect to the direction 144(i.e., the second unmanned vehicle 142 is ahead of the first unmannedvehicle 140). In some cases, the wind may push the gas plume 20 rapidlyin the direction 146 behind the second unmanned vehicle 142 and in frontof the first unmanned vehicle 140, such that the plurality of unmannedvehicles 184 may not detect the gas plume 20. Having the first unmannedvehicle 140 and the second unmanned vehicle 142 with the plurality oftarget surfaces in the row 124 may reduce a gap between adjacent targetsurfaces of respective adjacent unmanned vehicles 184.

FIG. 10 is a perspective view of another embodiment of the gas analysissystem 10 having the unmanned vehicle 12 (e.g., inspection drone)configured to sweep (e.g., oscillate or move) the light beam 28 whilefollowing the flight path 14 over the well pad 16 to detect the gasplume 20. In some embodiments, the unmanned vehicle 12 may be configuredto move the emitter 46 back and forth along an axis 148 as the unmannedvehicle 12 travels in the direction 144 and a direction 149 along theflight path 14 to sweep the light beam 28 and cover a larger area of thewell pad 16. For instance, sweeping the light beam may increase therange of the scan by the unmanned vehicle 12 and therefore reduce aduration in which the unmanned vehicle 12 travels along the flight path14. The main controller 13 may cause the unmanned vehicle 12 to moveback and forth along the axis 148, such that at least one light beamemitter 46 pivots back and forth between the left target surface 68 andthen back to the right target surface 70.

In some embodiments, the scanning micro-mirror 64 may be configured torotate the light beam 28 without moving the emitter 46 and/or theunmanned vehicle 12. The scanning micro-mirror 64 may direct the lightbeam 28 back and forth between the left target surface 68 and the righttarget surface 70. In some embodiments, the unmanned vehicle 12 isconfigured to sweep the plurality of light beams 28 to a respective lefttarget surface 68 and back to a respective right target surface 70.Sweeping the plurality of light beams 28 may increase a breadth of thescan at the current location along the flight path 14.

FIG. 11 is a perspective view of an embodiment of the gas analysissystem 10 emitting a plurality of light beams 28 in a multi-planararray. In some embodiments, the unmanned vehicle 12 has the plurality oflight beam emitters 46 configured to output the plurality of light beams28 in a multi-planar array. As shown in the illustrated embodiment ofFIG. 11, the unmanned vehicle 12 has the first light beam 100, thesecond light beam 104, the third light beam 108, and a fourth light beam150 directed at a first target surface 102, the second target surface106, the third target surface 110, and a fourth target surface 152respectively. Each light beam 100, 104, 108, 150 of the plurality oflight beams 28 may be offset from one another, such that theirrespective target surfaces 102, 106, 110, 152 are disposed at differentpositions. The first target surface 102 and the second target surface106 may be offset from each other in both a first direction (e.g., anx-axis 154) and a second direction (e.g., a y-axis 118) with respect toa surface 156 (e.g., ground surface 32) disposed directly below theunmanned vehicle 12.

The gas analysis system 10 may emit the plurality of light beams 28 in amulti-planar array to detect a shape of the gas plume 20. By using lightbeams 28 in a multi-planar array, the gas analysis system 10 maysimultaneously detect various features of the gas plume 20 alongmultiple axes, which may provide an indication of both a length (e.g., adistance in the y-axis 118 direction) and a width (e.g., a distance inthe x-axis 154 direction) of the gas plume 20. For example, the firstlight beam 100 and the third light beam 108 may be offset along thex-axis 154, and the second light beam 104 and fourth light beam 150 maybe offset along the y-axis 118. As a non-limiting example, the firstlight beam 100, the second light beam 104, and the fourth light beam 150may detect the gas plume 20 at a first location along the flight path14. At a second location (e.g., further along the flight path 14 in thex-direction) the second light beam 104 and the fourth light beam 150 maydetect the gas plume 20, but the first light beam 100 and the thirdlight beam 108 may not detect the gas plume 20. Further, at a thirdlocation (e.g., further still along the flight path 14 in thex-direction) the third light beam 108 may detect the gas plume 20, butthe first light beam 100, the second light beam 104, and the fourthlight beam 150 may not detect the gas plume 20. Thus, the controller 34may determine that the shape 158 of the gas plume 20 is wider than thedistance between the second light beam 104 and the fourth light beam150, and narrower than the distance between the first light beam 100 andthe third light beam 108. Having additional light beams 28 emitted fromthe unmanned vehicle 12, sweeping (e.g., rotating, oscillating, orotherwise moving) the plurality of light beams 28, and performingmultiple scans proximate the detected gas plume 20 may provideadditional data to identify a two-dimensional shape of the gas plume 20with respect to the x-axis 154 and the y-axis 118.

FIG. 12 is perspective view of an embodiment of the gas analysis system10 having the unmanned vehicle 12 (e.g., inspection drone 12) emittingthe plurality of light beams 28 to determine a shape 158 of the gasplume 20. For example, in addition to determining a length 160 and awidth 162 of the gas plume 20, the spectroscopy assembly 22 may beconfigured to determine a height 164 of the gas plume 20 in a verticaldirection (e.g., along a z-axis 166) to obtain further data related tothe shape 158 of the gas plume 20. As shown in the illustratedembodiment of FIG. 12, both a cylindrical gas plume 168 and anelliptical gas plume 170 may be present along the flight path 14. Atwo-dimensional scan using the light beam 100 may determine the width162 (e.g., along the x-axis 154) and the length 160 (e.g., along they-axis 118) of both the cylindrical gas plume 168 and the elliptical gasplume 170. In some cases, the two-dimensional scan may indicate that thecylindrical gas plume 168 and the elliptical gas plume 170 have the sameshape 158 (e.g., two-dimensional shape when viewed from above withrespect to the ground surface 32).

Accordingly, the gas analysis system 10 may be configured to emit thesecond light beam 104 at an angle offset from the first light beam 100,which may be emitted in the downward direction, to further determine theshape 158 of the gas plume 20. For example, the first light beam 100 maybe emitted toward the first target surface 102 and the second light beam104 may be emitted toward the second target surface 106 with respect toa location of the unmanned vehicle 12. At the location of the unmannedvehicle 12, the first light beam 100 may pass through the gas plume 20such that the gas analysis system 10 detects the gas plume 20. At asecond location of the unmanned vehicle 12 (e.g., further along theflight path 14 along the x-axis 154), the unmanned vehicle may move suchthat the second target surface moves to the previous location of thefirst target surface (e.g., location of the first target surface at thefirst location of the unmanned vehicle). However, although the secondlight beam 104 is directed at the same location of the previous firsttarget surface, the second light beam 104 may not detect the gas plume20. In such a case, the gas plume 20 may have an elliptical shape. Thefirst target surface 102 at the first location of the unmanned vehiclemay be disposed below an edge of the elliptical shape. The first lightbeam 100, emitted directly downward may pass through the edge of theelliptical shape; however, the second light beam 104, which is emittedat an angle offset from the first light beam 100 may pass under the edgeof the elliptical shape due to the angle of the second light beam 104and not pass through the gas plume 20. Thus, the controller 34 maydetermine that the gas plume 20 has a non-uniform cross-section alongthe z-axis 166 (e.g., elliptical shape, spherical shape, etc.) based onthe detection of the gas plume 20 by the first light beam 100 at thefirst location of the unmanned vehicle 12 and not detecting the gasplume 20 by the second light beam 104 at the second location of theunmanned vehicle 12. Specifically, the controller 34 may determine thatthe cross-section of the gas plume 20 along the z-axis 166 is smaller ata bottom portion of the gas plume 20. The controller 34 may beconfigured to analyze data received from the plurality of detectors overa plurality of locations of the unmanned vehicle 12 to determine a shape158 of the gas plume 20.

Further, the spectroscopy assembly 22 may be configured to determine theshape 158 of the gas plume 20 based at least in part on a change inspectral intensity of the plurality of light beams 28 emitted via thespectroscopy assembly 22. For example, as the unmanned vehicle 12travels along the flight path 14, the first light beam 100 may detect alower concentration of gas proximate a first side 172 of the ellipticalgas plume 170. As the unmanned vehicle 12 continues along the flightpath 14, the concentration may increase to a maximum concentration ofgas at a center of the gas plume 20. Further, the concentration of theelliptical gas plume 170 may decrease as the unmanned vehicle 12 movesfrom the center of the gas plume 20 to a second side 174 of the gasplume 20. Based on concentration data of the elliptical gas plume 170,the controller 34 may determine that a cross-section of the gas plume 20differs along the height 164 of the gas plume 20. Thus, the controller34 may utilize the concentration data to further characterize andanalyze the shape 158 of the gas plume 20.

In some embodiments, the gas analysis system 10 is configured todetermine the shape 158 of the gas plume 20 based at least in part on achange in spectral intensity of the plurality of light beams 28 emittedvia the spectroscopy assembly 22 and a wind condition. For example, thewind condition may include wind blowing the gas plume 20 in a directionopposite the direction of travel of the unmanned vehicle 12 along theflight path 14. The gas plume 20 may move at substantially the samespeed as the wind. For example, the wind may be blowing at five mph, andthe gas plume 20 may be moving at five mph. The unmanned vehicle 12 maybe moving at five mph along the flight path 14. Due to the gas plume 20traveling in the opposite direction of the unmanned vehicle 12, the gasplume 20 may appear to have a smaller shape than an actual shape of thegas plume 20 without taking into account the wind condition.Specifically, the gas analysis system may determine that the length ofthe gas plume 20 is shorter than the actual length of the gas plume 20without taking into account the wind condition. The controller 34 may beconfigured to account for movement of the gas plume 20 due to the windcondition when determining the shape 158 of the gas plume 20.

FIG. 13 is a perspective view of an embodiment of the first unmannedvehicle 140 inspecting the gas plume 20 in a high wind condition 176 andthe second unmanned vehicle 142 inspecting the gas plume 20 in a lowwind condition 178. In some embodiments, the spectroscopy assembly 22may be configured to determine a flow rate of gas through the location18 of the pipeline 134 and/or the well pad 16. In the presentembodiment, the well pad 16 includes gas being emitted from a firstlocation 180 and a second location 182. The first location 180 and thesecond location 182 may emit gas at substantially the same flow rate.For example, the first location 180 and the second location 182 may emitgas at a flow rate of fifty parts per million per minute. The high windcondition 176 may cause the gas to move away from the first location 180faster than the low wind condition 178 may cause the gas to flow awayfrom the second location 182. Additionally, a concentration of the gasmay decrease as the gas flows further from the location 18. In someembodiments, the concentration decreases relative to a speed at whichthe gas flows away from the location 18. For example, gas flowing awayfrom the location 18 at a high speed will likely have a lowerconcentration as compared to a gas flowing away from the location 18 ata low speed as a result of more rapid diffusion with surrounding air.Thus, the wind speed at position of the gas plume 20 may be utilized asa parameter for determining the flow rate of gas from location 18.

Moreover, the spectroscopy assembly 22 may be configured to determine aconcentration of the gas plume 20. The light beam 28 may have awavelength corresponding to an absorption frequency of the gas in thegas plume 20, such that at least a portion of the light beam 28 isabsorbed as it passes through the gas plume 20. The spectroscopyassembly 22 may determine a concentration of the gas plume 20 based atleast in part on a change of spectral intensity of the light beam 28passing through the gas plume 20. For instance, the spectral intensityof a light beam 28 may decrease as a concentration of the gas plume 20increases. Similarly, the spectral intensity of the light beam 28 mayincrease as a concentration of the gas plume 20 decreases. In otherwords, the spectral intensity of the light beam 28 and the concentrationof the gas plume 20 may be inversely proportional to one another.

Further, the spectroscopy assembly 22 may determine the shape 158 of thegas plume 20 using the techniques described above. Specifically, the gasanalysis system 10 may emit the plurality of light beams 28 and detect aconcentration of the gas plume 20 for each light beam 28 of theplurality of light beams 28 as the unmanned vehicle 12 moves along theflight path 14 to determine the shape 158 of the gas plume 20. Thecontroller 34 may be configured determine the gas flow rate of the gasemitted from the location 18 based at least in part on a change in theshape 158 of the gas plume 20 over time, a concentration of the gasplume 20 over a period of time, and/or the wind conditions. For example,the main controller 13 may compare the shape 158 (e.g., volumetricclassification) and concentration of the gas plume 20 at a first periodof time to the shape 158 and concentration of the gas plume 20 at asecond period of time to determine a change in the amount of gas in thegas plume 20. Moreover, the main controller 13 may be configured todetermine the gas flow rate of the gas emitted from the location 18based at least in part on the change in the amount of gas in the gasplume 20 with respect to an amount of time elapsed between the firstperiod of time and the second period of time.

This written description uses examples to disclose the embodiments ofthe present disclosure, including the best mode, and also to enable anyperson skilled in the art to practice the embodiments of the presentdisclosure, including making and using any devices or systems andperforming any incorporated methods. The patentable scope of the presentdisclosure is defined by the claims, and may include other examples thatoccur to those skilled in the art. Such other examples are intended tobe within the scope of the claims if they have structural elements thatdo not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. A gas analysis system, comprising: a spectroscopy assembly coupled toa scanning platform, wherein the spectroscopy assembly comprises: amultiplexer configured to combine a plurality of light beams into amultiplexed light beam, wherein the multiplexer is configured to directthe multiplexed light beam toward a target surface; a collection opticconfigured to receive a reflected multiplexed light beam from the targetsurface; and a controller configured to de-multiplex the multiplexedlight beam into a plurality of reflected light beams and determine aspectral intensity of each reflected light beam of the plurality ofreflected light beams.
 2. The gas analysis system of claim 1, whereinthe controller is configured to detect a gas based at least in part onthe spectral intensity of a reflected light beam of the plurality ofreflected light beams.
 3. The gas analysis system of claim 1, whereinthe controller is configured to detect a first target fluid based atleast in part on a first spectral intensity of a first reflected lightbeam of the plurality of reflected light beams and a second target fluidbased at least in part on a second spectral intensity of a secondreflected light beam of the plurality of reflected light beams.
 4. Thegas analysis system of claim 1, wherein each light beam of the pluralityof light beams comprises a respective predetermined wavelength range,wherein a first predetermined wavelength range is different from asecond predetermined wavelength range, and wherein the firstpredetermined wavelength range corresponds to a first absorptionfrequency of a first target fluid and the second predeterminedwavelength range corresponds to a second absorption frequency of asecond target fluid.
 5. The gas analysis system of claim 1, wherein thespectroscopy assembly is configured to emit a plurality of multiplexedlight beams, wherein each multiplexed light beam of the plurality ofmultiplexed light beams is emitted toward a respective target surface ofa plurality of target surfaces.
 6. The gas analysis system of claim 5,wherein the spectroscopy assembly comprises a plurality of multiplexers,wherein each multiplexer of the plurality of multiplexers is configuredto emit a respective multiplexed light beam of the plurality ofmultiplexed light beams.
 7. The gas analysis system of claim 1, whereinthe spectroscopy assembly comprises a plurality of emitters, whereineach emitter of the plurality of emitters are oriented to direct theplurality of light beams toward the multiplexer.
 8. The gas analysissystem of claim 1, wherein the controller comprises a de-multiplexerconfigured to de-multiplex the multiplexed light beam into the pluralityof reflected light beams.
 9. The gas analysis system of claim 1,comprising a user interface, wherein the user interface is configured tosend a signal to the controller indicative of a predetermined wavelengthrange for a light beam of the plurality of light beams.
 10. A gasanalysis system, comprising: an unmanned aerial vehicle; and aspectroscopy assembly coupled to the unmanned aerial vehicle, whereinthe spectroscopy assembly comprises: a multiplexer configured to combinea plurality of light beams into a multiplexed light beam; a scanningmirror configured to direct the multiplexed light beam toward a targetsurface; and a collection optic configured to receive a reflectedmultiplexed light beam from the target surface; and a controllerconfigured to de-multiplex the reflected multiplexed light beam into aplurality of reflected light beams, and wherein the controller isconfigured to determine a spectral intensity of each reflected lightbeam of the plurality of reflected light beams.
 11. The gas analysissystem of claim 10, wherein the scanning mirror is configured to rotateto adjust a position of the multiplexed light beam with respect to aground surface.
 12. The gas analysis system of claim 11, wherein thescanning mirror is configured to rotate between a first angle and asecond angle to move the multiplexed light beam from the target surfaceto an additional target surface.
 13. The gas analysis system of claim10, wherein the spectroscopy assembly comprises an emitter configured toemit the plurality of light beams toward the multiplexer.
 14. The gasdetection system of claim 10, wherein the spectroscopy assemblycomprises a collimator configured to collimate the multiplexed lightbeam such that the plurality of light beams of the multiplexed lightbeam are aligned substantially parallel to one another.
 15. The gasanalysis system of claim 10, wherein the controller is configured todetect a target fluid based at least on the spectral intensity of alight beam of the plurality of light beams.
 16. The gas analysis systemof claim 10, comprising a spectroscopy assembly housing configured tocouple to the unmanned aerial vehicle, wherein the spectroscopy assemblyhousing is configured to house the collection optic and at least onedetector.
 17. The gas analysis system of claim 10, wherein thecontroller is configured to execute the flight path for the unmannedaerial vehicle.
 18. A method comprising: combining a plurality of lightbeams into a single multiplexed light beam; emitting the singlemultiplexed light beam toward a target surface; receiving a reflectedmultiplexed light beam from the target surface; de-multiplexing thereflected multiplexed light beam into a plurality of reflected lightbeams; and determining a spectral intensity of each reflected light beamof the plurality of reflected light beams.
 19. The method of claim 18,comprising detecting a gas plume based at least in part on the spectralintensity of a reflected light beam of the plurality of reflected lightbeams.
 20. The method of claim 18, comprising emitting each light beamof the plurality of light beams at a wavelength range corresponding toan absorption frequency of a target fluid.